Abstract:
The results of a joint scientific work by the Iranian researchers at the University of Tehran and Research Institute of Petroleum Industry (RIPI) revealed new insights into the thermal properties of carbon nanotubes.

Iranian Researchers Gain New Insight into Thermal Properties of Nanotubes

Tehran, Iran | Posted on April 21st, 2012

The findings can have a significant impact on the performance of heat exchangers, drilling muds and cements.

The research group initially prepared five different structures of carbon nanotubes with varying number of walls through the CVD method and subsequently functionalized them by alkali salts to yield super stable nanofluids of each type. As a final part of their analysis, the researchers measured the thermal conductance of the synthesized nanofluids as a function of temperature and time. In addition, the researchers appraised the stability of the mentioned nanofluids through three different methods for the sake of completeness.

As a corollary derived from the research, increasing the layers of nanotubes is in favor of the apparent thermal conductivity. This is attributed to an increased effective contact surface due to existence of more layers and the influence of the layer thicknesses.

"The adopted method to functionalize the nanotubes had been originally intended for treatment of single wall carbon nanotubes, however, we managed to use it for other CNT structures after some refinements. Consequently, prolonged stability duration (more than six months) as well as less destructive effects caused by the utilization of acids were achieved. In fact, we took advantage of potassium persulfate as the oxidizing agent to bypass the need for acids or inorganic solvents. In summary, our approach features economy, compatibility with the environment, ease of practicality and operation," Ayda Nasiri, a member of the research group, explained.